With diversification of devices including a smart phone, a tablet terminal, a wearable computer, and the like, various services on the Internet of Things (IoT) are becoming realized. In the Internet of things (IoT) service, as an example, media data sensed by a camera or a microphone mounted on the device are used. For example, there is an IoT service that records conversation or activities of an operator positioned on a site through the media data, or manages a position or a state of the operator on the site identified from the media data.
Related technologies are disclosed in, for example, Japanese Laid-Open Patent Publication Nos. 2015-156662 and 2003-274049, and Japanese National Publication of International Patent Application No. 2011-517389.